Introduction: Gastric cancer represents a major public health challenge worldwide due to its significant morbidity and mortality rates. Among the factors associated with the development of gastric cancer, estrogen receptor beta (ERβ) has emerged as a potential therapeutic target. The aim of the study was to investigate the relationship between ERβ expression and gastric cancer.

Patients and Methods: English medical literature searches were conducted for ERβ expression in patients with gastric cancer vs. healthy controls. Searches were performed up to August 31, 2023, using MEDLINE, PubMed, Embase, and Google Scholar. Meta-analysis was performed using Comprehensive Meta-Analysis Software (Version 4, Biostat Inc., Englewood, NJ, USA). Pooled odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated. Heterogeneity was evaluated using the Cochran Q test, and it was considered present if the Q test p-value was less than 0.10. I2 statistic was used to measure the proportion of inconsistency in individual studies, with I2 > 50% representing heterogeneity. We also calculated a potential publication bias.

Results: Six studies representing 11 sub-studies were selected according to the inclusion criteria. The odds ratio of ERβ expression in fixed effect analysis was 0.347, 95% CI 0.270-0.445, 65.3% lower in gastric cancer than in normal mucosa. Heterogeneity and inconsistency were low, and no publication bias was demonstrated.

Conclusions: This meta-analysis showed that ERβ expression is lower in gastric cancer biopsy specimens than in healthy controls, which may have a significant effect on the survival of the patients.